Micro-channel heat exchanger including independent heat exchange circuits and method

ABSTRACT

A micro-channel heat exchanger including a first micro-channel heat conduit having a first end section that extends to a second end section through an intermediate section. The intermediate section includes a plurality of substantially straight sections and a plurality of bend sections that establish a first serpentine path. The micro-channel heat exchanger also includes a second micro-channel heat conduit having a first end portion that extends to a second end portion through an intermediate portion. The intermediate portion includes a plurality of substantially straight portions and a plurality of bend portions that establish a second serpentine path. The first serpentine path extends adjacent to the second serpentine path with the plurality of bend portions being interposed between the plurality of bend sections.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a National Stage Application of PCT Application No.PCT/US11/52480 filed Sep. 21, 2011, the disclosure of which isincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

Exemplary embodiments pertain to the art of heat exchangers and, moreparticularly, to a micro-channel heat exchanger including independentheat exchange circuits.

Conventional micro-channel heat exchangers include micro-channel tubesformed in a single serpentine path through which passes a coolant orrefrigerant. A fluid flow, such as air, is passed over the micro-channeltubes. The fluid flow exchanges heat with the refrigerant. The exchangeof heat results in a temperature change of the fluid flow. The exchangeof heat is enhanced through the addition of fins that extend between themicro-channel tubes. In certain systems, the micro-channel tubes passbetween an inlet header and an outlet header. Fins extend betweenadjacent micro-channel tubes to enhance heat exchange. When multiple,independent heat exchange paths are desired, the inlet and outletheaders are divided into distinct sections. Each section can then beoperated independent of the other.

BRIEF DESCRIPTION OF THE INVENTION

Disclosed is a micro-channel heat exchanger including a firstmicro-channel conduit having a first end section that extends to asecond end section through an intermediate section. The intermediatesection includes a plurality of substantially straight sections and aplurality of bend sections that establish a first serpentine path. Themicro-channel heat exchanger also includes a second micro-channelconduit having a first end portion that extends to a second end portionthrough an intermediate portion. The intermediate portion includes aplurality of substantially straight portions and a plurality of bendportions that establish a second serpentine path. The first serpentinepath extends adjacent to the second serpentine path with the pluralityof bend portions being interposed between the plurality of bendsections.

Also disclosed is a method of forming a micro-channel heat exchanger.The method includes forming a first micro-channel conduit having a firstend section that extends to a second end section through an intermediatesection, and creating a first serpentine path in the first micro-channelconduit. The first serpentine path includes a plurality of substantiallystraight sections and a plurality of bend sections. The method alsoincludes forming a second micro-channel conduit having a first endportion that extends to a second end portion through an intermediateportion, and creating a first serpentine path in the secondmicro-channel conduit. The second serpentine path includes a pluralityof substantially straight portions and a plurality of bend portions. Thefirst micro-channel conduit is positioned adjacent the secondmicro-channel conduit such that the plurality of bend portions areinterposed between the plurality of bend sections. Adjacent ones of theplurality of substantially straight sections and substantially straightportions are connected.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 depicts a micro-channel heat exchanger including independent heatexchange circuits in accordance with an exemplary embodiment;

FIG. 2 is a partial detailed view of a first portion of themicro-channel heat exchanger of FIG. 1;

FIG. 3 is a partial detailed view of a second portion of themicro-channel heat exchanger of FIG. 1; and

FIG. 4 is a partial cut-away view of the second portion of themicro-channel heat exchanger of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

With reference to FIGS. 1-4, a micro-channel heat exchanger constructedin accordance with an exemplary embodiment is indicated generally at 2.Micro-channel heat exchanger 2 includes a first micro-channel conduit 4that defines a first heat exchange circuit (not separately labeled) anda second micro-channel conduit 6 that defines a second heat exchangecircuit (also not separately labeled). First micro-channel conduit 4includes a first end section 10 that extends to a second end section 11through an intermediate section 12. First end section 10 is fluidlycoupled to an inlet member 14 and second end section 11 is fluidlycoupled to an outlet member 15. Inlet member 14 is configured to receivea fluid, for example, a first refrigerant. Intermediate section 12includes a plurality of substantially straight sections 17-28, a firstplurality of bend sections 30-34, and a second plurality of bendsections 40-45 that collectively define a first serpentine path 47.

Similarly, second micro-channel conduit 6 includes a first end portion60 that extends to a second end portion 61 through an intermediateportion 62. First end portion 60 is fluidly coupled to an inlet member64 and second end portion 61 is fluidly coupled to an outlet member 65.Inlet member 64 is configured to receive a second fluid such as a secondrefrigerant. The second refrigerant can be the same as, or distinct fromthe first refrigerant depending upon desired heat exchange parameters.In a manner also similar to that described above, intermediate portion62 includes a plurality of substantially straight portions 67-78, afirst plurality of bend portions 80-84, and a second plurality of bendportions 90-95 that collectively define a second serpentine path 97 thatis fluidly isolated from the first serpentine path 47. Eachmicro-channel conduit 4, 6 includes a plurality of micro-channels suchas indicated at 100 in connection with second micro-channel conduit 6 inFIG. 4.

In accordance with the exemplary embodiment, the first serpentine path47 extends adjacent to the second serpentine path 97 with the secondplurality of bend portions 40-45 being interposed between the firstplurality of bend portions 80-85 and the second plurality of bendportions 90-95 being interposed between the first plurality of bendsections. In this manner, first micro-channel conduit 4 is interleavedwith second micro-channel conduit 6. The term “interleaved” should beunderstood to describe that a portion of the plurality of straightsections 17-28 extend adjacent to other ones of the plurality ofstraight sections 17-28, while another portion of the plurality ofstraight sections 17-28 extends adjacent to select ones of the pluralityof straight portions 67-78. Similarly, a portion of the plurality ofstraight portions 67-78 extend adjacent to other ones of the pluralityof straight portions 67-78, while another portion of the plurality ofstraight portions 67-78 extend adjacent to select ones of the pluralityof straight sections 17-28.

In further accordance with an exemplary embodiment, micro-channel heatexchanger 2 includes a first plurality of fins or centers 110 and asecond plurality of fins or centers 115. First plurality of centers 110extend between adjacent one of substantially straight sections 17-28 andadjacent ones of the substantially straight portions 67-78. That is, thefirst plurality of centers 110 extend between substantially straightsections or substantially straight portions associated with the samemicro-channel conduit 4 or 6. More specifically, the first plurality ofcenters 110 are associated solely with either the first serpentine path47 or the second serpentine path 97. In contrast, the second pluralityof centers 115 extend between adjacent ones of the plurality of straightportions 17-28 and adjacent ones of the plurality of substantiallystraight portions 67-78. That is, the second plurality of centers 115extend between substantially straight sections and substantiallystraight portions associated with the both first micro-channel conduit 4and micro-channel conduit 6. More specifically, the second plurality ofcenters 115 join the first and second serpentine paths 47 and 97. Atthis point, it should be understood that although only two micro-channelconduits are shown, the number of micro-channel conduits employed bymicro-channel heat exchanger 2 can vary.

With this arrangement, refrigerant can be passed through firstmicro-channel conduit 4, second micro-channel conduit 6 or both firstand second micro-channel conduits 4 and 6. When refrigerant is passedthrough both micro-channel conduits 4 and 6, a fluid flow passing acrossthe first and second plurality of centers exchanges heat with therefrigerant in both micro-channel conduits 4 and 6. The heat exchangesurface area comprises the entire surface area of micro-channel heatexchanger 2. Similarly, if refrigerant is passed through one or theother of first and second micro-channel conduits 4 or 6, a fluid flowpassing across the first and second plurality of centers exchanges heatwith the refrigerant in flowing in the one of the micro-channel conduits4 and 6. In this manner, the heat exchange surface area remains theentire surface area of micro-channel heat exchanger 2. Accordingly,exemplary embodiments enhance heat exchange in a micro-channel heatexchanger having multiple, distinct circuits. That is, in contrast toprior art arrangements in which only that portion of the fluid flowpassing across an active circuit, e.g., upper or lower portions of theheat exchanger, the heat exchanger in accordance with the exemplaryembodiment utilizes substantially the entire fluid flow passing over theheat exchanger.

While the invention has been described with reference to an exemplaryembodiment or embodiments, it will be understood by those skilled in theart that various changes may be made and equivalents may be substitutedfor elements thereof without departing from the scope of the invention.In addition, many modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodiment disclosedas the best mode contemplated for carrying out this invention, but thatthe invention will include all embodiments falling within the scope ofthe claims.

1. A micro-channel heat exchanger comprising: a first micro-channel heat conduit having a first end section that extends to a second end section through an intermediate section, the intermediate section including a plurality of substantially straight sections and a plurality of bend sections that establish a first serpentine path; and a second micro-channel heat conduit having a first end portion that extends to a second end portion through an intermediate portion, the intermediate portion including a plurality of substantially straight portions and a plurality of bend portions that establish a second serpentine path, the first serpentine path extending adjacent to the second serpentine path with the plurality of bend portions being interposed between the plurality of bend sections.
 2. The micro-channel heat exchanger according to claim 1, wherein the first micro-channel heat conduit is fluidly isolated from the second micro-channel heat conduit.
 3. The micro-channel heat exchanger according to claim 1, a plurality of centers extending between adjacent ones of the plurality of substantially straight sections and plurality of substantially straight portions.
 4. The micro-channel heat exchanger according to claim 1, a plurality of centers extending between adjacent ones of the plurality of substantially straight portions.
 5. The micro-channel heat exchanger according to claim 1, wherein the plurality of bend sections includes a first plurality of bend sections and a second plurality of bend sections.
 6. The micro-channel heat exchanger according to claim 5, wherein the plurality of bend portions includes a first plurality of bend portions and a second plurality of bend portions.
 7. The micro-channel heat exchanger according to claim 6, wherein the second plurality of bend portions is interposed between the first plurality of bend portions.
 8. The micro-channel heat exchanger according to claim 7, wherein the second plurality of bend portions is interposed between the first plurality of bend sections.
 9. A method of forming a micro-channel heat exchanger, the method comprising: forming a first micro-channel heat conduit having a first end section that extends to a second end section through an intermediate section; creating a first serpentine path in the first micro-channel heat conduit, the first serpentine path including a plurality of substantially straight sections and a plurality of bend sections; forming a second micro-channel heat conduit having a first end portion that extends to a second end portion through an intermediate portion, the intermediate portion; creating a first serpentine path in the second micro-channel heat conduit, the second serpentine path including a plurality of substantially straight portions and a plurality of bend portions; positioning the first micro-channel heat conduit adjacent the second micro-channel heat conduit such that the plurality of bend portions are interposed between the plurality of bend sections; and connecting adjacent ones of the plurality of substantially straight sections and substantially straight portions.
 10. The method of claim 9, further comprising: connecting adjacent ones of the plurality of substantially straight portions.
 11. The method of claim 9, wherein connecting adjacent ones of the plurality of substantially straight sections and substantially straight portions comprises joining the adjacent ones of the plurality of substantially straight sections and substantially straight portions with a plurality of centers.
 12. The method of claim 11, wherein connecting adjacent ones of the plurality of substantially straight portions comprises joining the adjacent ones of the plurality of substantially straight portions with a plurality of centers. 